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Free keywords:
magnetisation dynamics;time-resolved Kerr rotation;complex oxides;superlattice;multilayer
Abstract:
Laser-induced magnetisation dynamics of a La0.7Sr0.3MnO3/SrRuO3 superlattice is studied by means of a single-colour optical pump-probe technique. Significant differences in the magnetisation dynamics of a superlattice with respect to the single layers of constituent materials are demonstrated. Below the Curie temperature TC of SrRuO3, laser-induced ultrafast demagnetisation is found to be followed by a uniform precession of the magnetisation around its new equilibrium. The data is described within a simple model based on a displacive excitation of a precessional magnetisation dynamics. The model is shown to give a good fit to the experimental data. As the initial temperature approaches TC, the oscillations get suppressed and eventually vanish. The magnetisation dynamics is shown to depend on whether the two distinct magnetisation vectors in the superlattice are ferromagnetically or antiferromagnetically aligned
